The present invention relates to progressing cavity devices, and more particularly to stators of progressing cavity devices that can pass fluids containing solids.
Progressing cavity pumps are frequently used in applications to handle highly viscous fluids and fluids containing solids. Depending on the size and shape of the solids, the pump can frequently pass the solids through the pump if the solid is smaller than the cavity volume within the pump. If the solids are larger than the cavity then the solids can get jammed between the rotor and stator and cause the pump to lock up.
Power sections are used on directional drilling motors to provide the rotary motion to the drill bit as drilling mud is pumped through the power section. The usual failure mechanism for the power section stator is chunking of the rubber as it fatigues due to cyclic loading. The chunking usually commences at the end of the stator where the rotor is connected to the bearing assembly of the motor due to the sideload from the constant velocity joint or flex shaft. The chunking mechanism results in pieces of rubber breaking off of the rubber power section stator profile. These pieces of rubber can travel through the drilling motor and into the drill bit where they can plug the bit nozzles. If the bit nozzles become plugged then the drilling mud can no longer be pumped through the motor and the drilling operation has to stop resulting in costly downtime.